853
FXUS62 KRAH 060623
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
225 AM EDT Thu Jun 6 2024

.SYNOPSIS...
A pre-frontal trough and cold front will move across the area
Thursday evening through early Friday. High pressure will move in
with cooler and drier air for the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 225 AM Thursday...

...There is a Level-1 (Marginal Risk) For Severe Storms this
afternoon and early evening...

...Gusty wind is expected to be the primary hazard with the stronger
storms and isolated storms may reach severe limits...

The mid/upper trough moving through the Great Lakes states will send
a pre-frontal trough through central NC this afternoon and evening.
Central NC will be removed from much influence of the upper trough;
however, strong heating will allow for MLCAPE to reach near 2000
J/kg during peak heating. In addition, a deep W-SW flow and bulk
shear around 20 knots may also aid in organization of storms.

Scattered thunderstorms should form on the pre-frontal trough and
possible evolve into a line of showers/thunderstorms as it moves ESE
aross our region. The most likely timing would be around 19z-22z in
the Triad, then 21z-02z in the Triangle and points south and east.
The line of showers/storms will eventually move east of the region
this evening.

The cold front will arrive later tonight, but little if any
showers/storms are expected after the pre-frontal trough sweeps most
of the MLCAPE and moisture out of the region.

Highs today should reach the mid to upper 80s NW ranging into the
lower 90s SE. Lows tonight will be in the 60s.

&&

.SHORT TERM /FRIDAY and FRIDAY NIGHT/...
As of 225 AM Thursday...

...Lowering humidities and temperatures Friday and Friday night...

Mid and upper troughing will be along the eastern seaboard Friday
and Friday night. Central NC will be on the back side of the trough
with the axis moving offshore. CAA will drive the humidities and
even temperatures down from early June standards. With partly to
mostly sunny skies, highs will reach the lower to mid 80s NW ranging
into the mid to upper 80s east and south. Lows will dip into the 55-
60 range except lower 60s SE.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
As of 200 PM Wednesday...

Friday and Saturday: Aloft, an upper low will meander slowly
eastward through southern Ontario/southern Quebec, Canada Fri and
Sat. The attendant trough will progress eastward through the East
Coast states Fri as a s/w passes over central NC within the trough.
The trough will continue offshore Fri night. Nearly zonal flow
should prevail Sat/Sat night, with a weak s/w or two passing
overhead. At the surface, the cold front should be through central
NC Fri morning and continue eastward offshore through the aft/eve.
Cool high pressure centered just west of the southern Appalachians
will ridge eastward into the area Fri night. A trough may develop
over the area Sat and amplify Sat night, while the high weakens. For
now the forecast remains dry. Highs Fri ranging from low/mid 80s NW
to mid/upper 80s SE, with lows ranging from mid 50s north to mid 60s
south. Temps should be similar Sat/Sat night, highs a degree or two
lower and lows a couple/few degrees higher in some spots.

Sunday onward: There is still some uncertainty in this part of the
forecast, so confidence is on the low side. Aloft, as the parent low
swings through Quebec, Canada and the Northeast US a potent s/w will
drop south out of central Canada, through the northern Plains/upper
MS Valley Sat night/Sun, then continue around the parent low through
the Great Lakes/OH Valley Sun, amplifying the attendant trough in
the process. As the low lifts northward Sun night/Mon, the trough
should swing eastward into (GFS)/toward (ECMWF) the mid-Atlantic.
The s/w should move through central NC Mon night or Tue/Tue night.
At the surface, with the trough over central NC, a warm front may
briefly lift through the area Sun aft/eve, before another cold front
pushes through the area Sun eve/night. The front should stay east of
the area, with high pressure over the Plains/MS Valley through Mon
night. Beyond that, the medium-range guidance varies greatly, with
the ECMWF showing a low tracking along the Southeast US/Carolina
coast Mon night and Tue, while the GFS slowly develops a westward
retreating, inverted coastal trough Tue/Wed. The best chances for
showers/storms will largely be tied to the initial s/w sometime
between Sun eve and Mon night. Additional showers/storms will be
possible through mid-week, but confidence is low at this time.
Temperatures should be within a category or two of normal.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
As of 145 AM Thursday...

24-hour TAF period: Scattered patches of mid and high cloudiness
will stream across central NC, before IFR/MVFR stratus and
stratocumulus again develop late tonight by around 08-10z. The
highest confidence of this occurring is at the Triad terminals (INT
and GSO), followed by RDU and FAY, and lastly RWI. S/SW winds should
stay elevated overnight (around 5-10 kts) and this combined with the
low stratus fog is not expected to be a concern. Conditions
will improve to VFR by mid to late morning, but a line of showers
and thunder storms associated with a pre-frontal trough is
expected to move east through central NC during the afternoon and
evening. The best guess is for the line to reach the Triad terminals
by mid afternoon, followed by RDU near the end of the TAF period,
though timing is still a bit uncertain. MVFR or even IFR ceilings
and visibilities will be possible as the line moves through, along
with gusty winds.

Outlook: The line of showers and storms will continue to impact
southern and eastern parts of the area through the evening, with
sub-VFR conditions still possible. VFR conditions and dry weather
are expected to return Friday through the weekend.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...Badgett
NEAR TERM...Badgett
SHORT TERM...Badgett
LONG TERM...KC
AVIATION...Badgett/Danco